Laboratory balance



I Sept l, 1925.

, g -1,551,726 A capMJalRKV LABORATORY BALANCE Filed Feb. 16. '1922 INVENTOR z ,n LM;

By omeys,

ggf. y

Patented Sept. 1, 19725K.

UNITED Asirnres l? ATEN 'l` .OF F ICE..`

rGLOVER BIRK, `OF INDIANAPOLIS, INDIANA, ASSIGNOR TO THE TORSION BALANCE COMP-ANY, OF NEW YORK, N. Y.,

A 'CORPORATION OF NEW YORK.

LABORATORY BALANCE.

Application filed February Y16, 1922. Serial No. 537,098.

T0 @ZZ whom t 'may concern:

Be it known that Il, Gnovnn li/f. rnx, a citizen of the United States of America, residing in Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Laboratory Balances, of which the following is a specification.

The present invention relates to scales and laboratory balances, and aims to provide certain improvements therein.

Such balances are usually provided with a graduated index memberI ast which the pointer carried by the scale beam` moves. Then the balance is in proper adjustment, the beam upon being released from its support on the beam arrest will be balanced on its fulcrum axis and the. pointer 'will coincide with the zero on the index member. lVhen out of true equilibrium to varying conditions of temperature, level, or the like, affecting the. balance, the pointer will not coincide with the Zero of the index ineinber, but will tal-e a position at either side thereof. To remedy this the manipulation of the leveling screws or the adjustingscrevv Vusually carried by the balance beam must be resorted to. These means of adjustment usually take Considerable time and in actual practice many operators Will Weigh from the point (at either side of zero) at which the pointer indicates equilibrium rat-her than readjust the balance. j

According to the present invention I provide a simple and rapid means of adjusting the pointer at zero, and thus overcome the uncertainty and inconvenience of Weighing from an imaginary Zero. This is accomplished by making the index member or some indicator movable preferably laterally, in an arc, so that the zero thereon can be readily brought into coincidence with the pointer. The index member is designed to be manually moved, and preferably by means on the exterior of the case, in such balances that are housed. Suitable means are also provided for maintaining the index in adjusted position. The invention also comprehends certain other features of improvement which will be hereinafter more fully set forth.

Referring to the drawings:

Figure l is a front elevation of a balance having the invention embodied therein.

Fig. 2 is an enlarged elevation of the mov- !of any improved construction.

able index and the means for moving vthe closing case A having a slidable glass door B, said case enclosing the balance mechanism consisting of a column C supporting the beam arrest l), a bala-nce beam Esupporting a pair of scale pans F, F and carrying an indicator or pointer G, all of which maybe The pointer G is adapted to siving over or .past an index member H having graduations thereon, during the course of a Weighing operation. l 1

Preliminary to `comme-.icing any `Weighing operation it is important' that `the position of the pointer with relation yto `the zero .in-

dex be determined. It for any cause such as temperature change, level, or the like, the balance be out of equilibrium it is desirable for convenience that the Vpoiirer and zero index be brought into coincidence .before commencing the Weighing operation. According to the present invention this is accomplished in a simple and rapid manner by having for instance the index member H movable laterally With respect to the indicator so that by a slight lateral movement of the index member the zero and pointer may be brought into coincidence. In order to permit this lateral shifting of the index member H, I provide it with alatreral slot I adjacent its top through which passes a fastening member J connecting the member to the column C. Similar slots I and I2 are provided adjacent the bottom of the index member through which fastening means J and J 2 pass and connect the index member with a suitable support, herein shown as a bracket K fastened to the underside of the base of the balance. Lateral movement of theindex member H is accomplished by forming the lower edge of the member H as a rack L and having it geared to a Worm M mounted en a suitable sha'tt m which is rotatable by a. thumb Wheel N located at the side of the balance. The sha-'ft m which carries the Worm BI may be supported in any suitable i'nanner, herein shown as'braclet supports m. To insure against any accidental shifting of the index member' from its adjusted position the thumb Wheel N is provided with a lmurled or grooi'ed head a cooperating with a spring paivl or detent device O fastened to the balance case. Since the pointer G in its swinging movement describes an arc, it is preferable that the index member H be also movable in an arc. Such arcuate movement of the index member is provided by having the slots I, I, I2 ot arcuate form.

In Figs. 5 and 6 I have shoivn another manner of providing an adjustable index member. As herein shown itconsists of an arcuate band ID having indicia thereon and being slidable in a correspondingly shaped groove Q, formed in the face ot the supporting plate R. rI`he index member or band l) is movable laterally by means ot a manually operable arm S which carries a plate S secured to the back et the band ID by screws T. These screws T are movable in a slot U formed in the bacll: of the plate R, thus permitting the relative movement between the band P and plate R. To maintain the band I) in any position te which it has been moved, there is employed a flat spring V acting against the back o'l the plate R and serving to hold the band P in Ylirictional tight engagement in the groove Q. The supporting plate R may be suitably mounted at the column base et the balance by passing securing elements through the openings r located in the corners of the plate.

From the foregoing description it will be appreciated that I have provided suitable means for accomplishing' the objects hereinbefore set forth. In Figs. l to 4 I have shown the index member as being manually adjustable from the exterior of the balance case housing the balance mechanism, While in Figs. 5 and 6 I have shown the means for accomplishing this, as being arranged adjacent the index member. dersteod, however, that the arm S of the device shown in Figs. 5 and 6 might be extended through the base of the balance and outwardly to the trent tace thereof for manipulation Jirom the outside of the balance case.

lflfhile I have shown several embodiments o1 the invention I do not Wish to be limited to the specific details disclosed since various changes may be resorted to without depart ing :trom the spirit of the invention.

I c laim as my invention:

l. A scale or balance comprising a stand and an index member mounted thereon, and means tor manually adjusting the index member, comprising a rack carried by the index member.

2. A scale or balance comprising a stand anu an index member mounted thereon enclosed Within a case, and means tor manually adjusting the index member from the exterior ot the case, comprising a rack carried by the index member and a Worm controlled by a manually operable member on the outside et the case.

3. A scale or balance comprising a stand, a beam carrying a pointer, and a laterallyadjustable index member mounted on the stand, a case enclosing said members, means accessible exterior to the case tor adjusting the index member, and a springl holding the index member in adjusted position.

In Witness ivhereor', I have hereunto signed my name.

GLOVER M. BIRK.

It Will be un- (ill 

